In the processes of forming a dye image ordinarily by making use of a silver halide color photographic light-sensitive material, the dye image is formed in such a manner that the light-sensitive material is imagewise exposed to light and dye image may be formed upon reacting an oxidized p-phenylenediamine type color developing agent with a dye image forming coupler. In the above-mentioned processes, a subtractive color method is normally applied for reproducing colors, so that cyan, magenta and yellow dye images corresponding to red, green and blue are formed on the respective light-sensitive layers. In recent years, when forming such a dye image as mentioned above, a highly active development using a high pH, high temperature and high concentration type color developing agent and the ommission of some processing steps have popularly been tried with the purpose of saving a processing time. It is particularly essential to improve the rate of development in a color developing step so as to saving the developing time required for the above-mentioned highly active development.
Accordingly, in recent years, many measures have been taken to rapidly perform a color development. As one of the measures, it has been well known that a development accelerator is used when an exposed silver halide color photographic light-sensitive material is developed by making use of an aromatic primary amine type color developing agent. Among the development accelerators, the compounds endowed with a relatively higher activity have a disadvantage that a fog is often produced. In the meantime, even among the above-mentioned compounds, some kind of black-and-white developing agents displaying a superadditivity in a color development may be able to display a development accelerating effect with a relatively less fog poduction as compared with other development accelerators.
Such black-and-white developing agents include, for example, an 1-phenyl -3-pyrazolidone described in British Pat. No. 811,185, an N-methyl-p-aminophenol described in U.S. Pat. No. 2,417,514, an N,N,N',N',-tetramethyl-p-phenylene-diamine described in Japanese Patent Publication Open to Public Inspection (hereinafter called Japanese Patent O.P.I. Publication) No. 15554/1975, and so forth.
The superadditive development mechanism for color development has been reported by G.F. Van Veelen in "Journal of the Photographic Science", No. 20, p. 94, (1972). In the cases of obtaining a color development accelerating effect by making use of the above-mentioned black-and-white developing agent as an auxiliary developer, there is one case where such a black-and-white developing agent is contained in advance in a silver halide color photographic light-sensitive material or another case where the black-and-white developing agent is contained in a color developer.
Among the above-mentioned cases, in the case that the above-mentioned black-and-white developing aent is contained in a silver halide photographic light-sensitive material so as to accelerate the color development thereof, an 1-aryl-3 pyrazolidone, in particular, is preferably used. For example, Japanese Patent O.P.I. Publication No. 89739/1981 discloses that an 1-aryl-3-pyrazolidone is added to a silver halide color photographic light-sensitive material comprising a support bearing thereon silver halide emulsion layers containing silver halide grains different among the layers by 50% or more in terms of grain size ratios. However, the silver halide color photographic light-sensitive materials each containing an 1-aryl-3-pyrazolidone disclosed in the above-mentioned Patent Publication are to be treated in an intensifying process in the presence of such an intensifier as a cobalt complex salt. It was, therefore, found that, if they are treated in a normal color developing process, they will display the development accelerating effect very poorly and, in particularly, if they are treated in a normal color developing process by making use of silver halide emulsions each having a relatively large average grain size, almost no color development accelerating effect can be displayed.
Besides the above, Japanese Patent O.P.I. Publication No. 64339/1981 discloses a process in which an 1-aryl-3-pyrazol-idone having a specified structure is added into a silver halide color photographic light-sensitive material; and Japanese Patent O.P.I. Publication Nos. 144547/1982, 50532/1983, 50533/1983, 50534/1983, 50535/1983, and 50536/1983 each disclose the respective processes in which an 1-aryl-3-pyrazolidone is added into a silver halide color photographic light-sensitive material so as to develop the material within a substantially very short period of time.
The techniques disclosed in the above-mentioned patent publications may be satisfiable as far as a development accelerating effect is concerned, however, these techniques are not always satisfiable if they are evaluated in general terms including the photographic characteristics such as sensitivity, gradation, maximum density and so forth.
On the other hand, with respect to the silver halide emulsions each containing silver halide grains, which are used in silver halide photographic light-sensitive materials, it has already been proved that the configurations, sizes and compositions of the silver halide grains will substantially influence a developing rate, and many studies have so far been made. From these studies, it has also been proved that silver chloride grains will exhibit a substantially high developability under some specific condition and silver halide grains are advatageously used because they have less disadvantages than the aforementioned development accelerators have. The techniques of using silver cloride grains are described in, for example, Japanese Patent O.P.I. Publication Nos. 135832/1980, 16589/1980, 125612/1983 and 107532/1983; Japanese Patent Examined Publication No. 56055/1982; and so forth. However, silver chloride grains have such a disadvantage as is poor in antipressure effect, while they have a particularly excellent developability as compared with the other silver halide grains.
The antipressure effect of silver halide grains will now be described below:
Generally, various pressures are applied to light-sensitive materials. In the course of manufacturing light-sensitive materials, a great pressure is applied to such light-sensitive materials in a cutting step, for example.
Besides the above, when using light-sensitive materials and, particularly, sheet-type light-sensitive materials, they may often be bent because they are handled by hand and a pressure is applied to the bent portions of the materials.
On the other hand, it has become populerized in recent years that light-sensitive materials have been automatically exposed to light by a printer and have also been treated in an automatic development process by an automatic processor. Accordingly, there have been increased opportunities to apply mechanical pressures to light-sensitive materials inside the above-mentioned apparatuses. When a variety of pressures are applied to light-sensitive materials, as mentioned above, the pressures are also applied to the silver halide grains of such light-sensitive materials through gelatin that is the binder of the silver halide grains. When the pressure is applied to the silver halide grains, the photographic characteristic of the light-sensitive materials are varied so as to produce phenomena such as a pressure desensitization, a pressure fog and so forth. These kinds of phenomena have so far been well-known as the so-called photographic pressure effects such as described in, for example, T.H. James, `The Theory of the Photographic Process`, 4th Edition, The Macmillan Co., New York, Article 24; D. Dautrich, F. Granzer and E. Moiser, `Journal of Photographic Science`, No. 21, p. 221, 1973; and so forth.
It is also well-known in this field of the at that the greater in both grain-size and sensitivity silver halide grains are, the higher the sensibility for pressure is as well as the more a pressure desensitization or a pressure fog may be liable to produce.
Further, there are two cases of applying a pressure to a light-sensitive material, one is in a dry state and another is in a wet state where a development is being carried out. Therefore, any light-sensitive material cannot be fully satisfied until the antipressure effect thereof is improved in both of the above-mentioned two states.
There have so far been attempts to provide light-sensitive materials relatively less affected by pressure.
The well known methods of improving such antipressure effects include, for example, a method in which such a plasticizer as a polymer is contained into a light-sensitive material, another method in which a proportion of a silver halide content to a gelatin content is made lower, and so forth.
For example, British Patent No. 738,618 discloses a method in which a heterocyclic compound is used; British Patent No. 738,637 discloses a method in which an alkyl phthalate is used; British Pat. No. 738,639 discloses a method in which an alkyl ester is used; U.S. Pat. No. 2,960,404 discloses a method in which a polyvalent alcohol is used; U.S. Pat. No. 3,121,060 discloses a method in which a carboxyalkyl cellulose is used; Japanese Patent O.P.I. Publication No. 5017/1974 discloses a method in which paraffin and a carboxylate are used; Japanese Patent Examined Publiction No. 28086/1978 discloses a method in which an alkyl acrylate and an organic acid are used; and so forth.
However, the above-mentioned techniques have the disadvantages, for example, that the antipressure effects are not satisfactory in both dried and wet states and that the characteristics of the binder used such as the tackiness and dryness of the surface of a light-sensitive material and so forth are seriously deteriorated.
In addition to the above, the methods of improving the antipressure characteristics of silver halide grains include, for example, a method disclosed in Japanese Patent Examined Publication No. 23248/1982 in which an mercapto compound and a water-soluble iridium compound are to be added to a silver halide in the course of forming silver halide grains; another method disclosed in U.S. Pat. No. 3,622,318 in which a denatured emulsion which was surface-sensitized is used; and so forth. However, with the above-mentioned techniques, it is hard to enjoy a satisfactory antipressure effect in both dried and wet states.
Further, with the techniques, the antipressure effect is deteriorated relatively as the sensitivity of a light-sensitive material is getting faster or the grain sizes of silver halide grains is getting larger.
Accordingly, any of the conventional techniques cannot satisfactorily be effective to maintain the ascendance of silver chloride grains as well as to improve the antipressure effects in both dried and wet states and, therefore, a further improvement has been required.